Multi-purpose surgical tool system

ABSTRACT

A surgical tool system (20) with replaceable surgical cutting accessories (26) and attachments (34) for holding the tools. This system includes a handpiece (22) to which the cutting accessory and attachment are releasably attached. Collet (50) located inside a drill housing (44) located at one end of the handpiece securely fastens the surgical tool to a motor (24) also located in the handpiece. Leaf spring assembly (46) flush with the drill housing releasably secures the attachment in place. A single actuating collar (52) located around the outside of the drill housing both controls the locking force supplied by the collet and selectively relaxes the leaf spring assembly.

FIELD OF THE INVENTION

This invention relates generally to a surgical tool system and, moreparticularly, to a surgical tool system with a number of readilyinterchangeable components.

BACKGROUND OF THE INVENTION

In modern surgery one of the most important instruments available tomedical personnel is the powered surgical tool. Typically this toolcomprises some type of handpiece in which a motor is housed. Secured tothe handpiece is a cutting accessory designed to be applied to asurgical site on a patient in order to accomplish a specific medicaltask. For example, some powered surgical tools are provided with drillsor burrs for cutting bores into a hard tissue or for selectivelyremoving the hard tissue. Still other powered surgical tools areprovided with saw blades as the cutting accessories. These tools areused for separating large sections of hard and soft tissue. The abilityto use powered surgical tools on a patient has lessened the physicalstrain of physicians and other personnel when performing medicalprocedures on a patient. Moreover, most surgical procedures can beperformed more quickly and more accurately with powered surgical toolsthan with the manual equivalents that proceeded them.

While powered surgical tools have provided to be both an aid to patientsand medical personnel, they are not without some disadvantages. Aproblem with some surgical tools is that the handpiece and associatedinstrument are assembled as a single, permanently attached unit.Consequently, if for a particular medical procedure, it is necessary tofirst drill a bore in a bone and then to cut an elongated slot throughthe bone, it may be necessary for the doctor to be provided with twotools, each with its own cutting accessory. Furthermore, for some tasksduring the procedure the physician may want to use a tool with a headthat is substantially axially aligned with the handpiece. For othertasks during the same procedure the physician may want to use a toolwith a head that is angled relative to the handpiece. An advantage ofusing these tools is that they do not block the field of view around thesurgical site as much as tools with in-line heads.

There have been attempts to provide powered surgical tool systems whichallow for some interchangeability of the instruments with which the toolis used. Typically, these systems include a single handpiece that has acoupling assembly to which a number of different surgical cuttingaccessories can be attached. These systems allow the doctor working onthe patient to switch the cutting accessory being used with thehandpiece as the surgical procedure progresses. An advantage of thesesystems is that they significantly reduce the number of handpieces thatneed to be provided in a surgical setting.

There have been recent attempts to enhance the utility of handpieces byproviding complementary attachments. An attachment serves as the head ofthe handpiece to which the cutting accessory is attached. Someattachments are provided with some types of linkages that transfer themotive power from the motor internal to the handpiece to the cuttingaccessory. For example, some attachments are designed to provide anextended length to the handpiece. Still other attachments function asbent-angle units. These attachments direct the associated cuttingaccessory at an angle away from the axis of the handpiece so as toprovide the surgeon with an alternative view of the surgical site. Stillother attachments transfer the rotor motion of the motor internal to thehandpiece into either a reciprocating or oscillatory motion. Theseattachments make it possible to attach saw blades to handpieces that arenormally used with rotating cutting accessories. The development ofattachments has further expanded the utility of basic surgicalhandpieces.

While current multi-tool surgical tool systems have proved useful forreducing the number of tools needed when working on an individualpatient, they are not without some disadvantages. Many current surgicaltool systems are designed so that the individual elements forming atool, the handpiece and the complementary accessory, must be threadinglycoupled to each other. In some of these systems, in order to ensure apositive coupling, medical personnel are required to take a wrench tothe tool in order to provide the torque required to first couple theelements, and then, at a latter time to uncouple them.

Moreover, if the handpiece is provided with an attachment in addition toa cutting accessory, at a minimum the medical personnel must take timeto determine which component, the cutting accessory or the attachment,they are to remove from the handpiece. Moreover, if both the cuttingaccessory and the attachment are to be replaced, time must be spentreleasing and restoring the lock mechanisms that hold both these membersto the handpiece. At a minimum, the time medical personal spendperforming these coupling and uncoupling tasks only increases the timeit takes to perform the surgical procedure. However, the time needed toperform these tasks lengths the time it takes to perform the surgicalprocedure. Consequently, this lengthens the time the surgical site isopen and exposed to infection as well as the time patient is exposed toanesthesia. Moreover, there are instances where the time medicalpersonnel have to spend attending to the tool and not to the patient canpotentially adversely affect the well being of the patient.

Moreover, in order for these interchangeable power tools to be properlydesigned, they should ideally be provided with some type of lock outmechanism to prevent tool operation in the event the instrument is notfully coupled in place.

SUMMARY OF THE INVENTION

This invention relates to an improved multi-use powered surgical toolsystem that enables the medical personnel to easily and quickly coupledifferent surgical cutting accessories and attachments to a singlehandpiece. Still another feature of the surgical tool system of thisinvention is that it automatically inhibits operation of the tool in theevent the accessory is not properly coupled to the handpiece.

BRIEF DESCRIPTION OF THE DRAWINGS

This invention is pointed out with particularity in the claims. Theabove and further features of this invention may be better understood byreference to the following description taken in conjunction with theaccompanying drawings, in which:

FIG. 1 is a plan view of the basic components of the surgical toolsystem of this invention wherein the components are assembled to form atool;

FIG. 2 is a plan view of the components of FIG. 1 illustrating thecomponents partially decoupled from each other;

FIG. 3 is a cross sectional view of the components of FIG. 1illustrating the components in the assembled, tool run, state;

FIG. 4 is an exploded view of the interior located components that formthe coupling assembly of the handpiece;

FIG. 5 is an exploded view of the outer located components that form thecoupling assembly;

FIGS. 6A and 6B are, respectively, perspective and cross sectional viewsof the rotor shaft;

FIG. 7 is a detailed view of the collet housing;

FIGS. 8A and 8B are, respectively, detailed and cross sectional views ofthe collet;

FIG. 9 is a detailed view of the collet ring;

FIGS. 10A and 10B are, respectively, detailed side and cross sectionalviews of the rear drill housing;

FIG. 11 illustrates the relationship of the actuating collar to the leafspring;

FIG. 12 is a detailed outside view of the attachment housing;

FIGS. 13A and 13B are, respectively, detailed and cross sectional viewsof the shaft of a surgical instrument of the surgical tool system ofthis invention;

FIGS. 14A and 14B are, respectively cross sectional views illustratingthe relationship of the actuating collar and locking leaf spring to theattachment housing when the actuating collar is in the looked andunlocked state;

FIGS. 15A, 15B and 15C are cross sectional views of the surgical toolsystem of this invention when, respectively, the handpiece is in the runstate, the cutting accessory load state, and the attachment releasestate;

FIG. 16 is a cross sectional view of the attachment that is secured tothe handpiece; and

FIG. 17 is a perspective view illustrating how the surgical tool systemof this invention can be used with an angled attachment.

DETAILED DESCRIPTION

FIGS. 1-3 illustrate the basic components of a surgical tool system 20of this invention. System 20 includes a handpiece 22 in which a motor 24is housed. The motor 24 is energized by power supplied to the handpiece22 by a cable 21 releasably coupled to the bottom or base end 25 of thehandpiece. A surgical cutting accessory 26 is coupled to a head end 27of the handpiece 22, the end opposite the base end 25, to rotate inunison with the motor 24. The depicted cutting accessory 26 is a burrwith a spherical head 30 formed with cutting surfaces designed tofacilitate the removal of hard tissue. The cutting accessory 26 furtherincludes an elongated, cylindrical shaft 32, to which the head 30 isattached. The shaft 32 is the actual member of the cutting accessory 26that is coupled to the motor 24.

Surgical tool system 20 further includes an attachment 34 which is alsocoupled to the head end 27 of the handpiece 22. Attachment 34 includesan attachment housing 36. The attachment housing 36 is the member of theattachment 34 that is physically coupled to the handpiece 22. Anattachment sleeve 38 is fixedly coupled to the narrow diameter head endof the attachment housing 36. As will be described hereinafter,attachment housing 36 and attachment sleeve 38 are formed with a bore40. Bore 40 is occupied by the shaft 32 of the cutting accessory 26which extends through the attachment 34. When the surgical tool system20 is in use, the accessory shaft 32 will bear against attachmentbearings 267 in sleeve 38 as a result of loads imposed on the cuttingaccessory 26. The attachment 34 thus provides the physical support forthe cutting accessory 26 so as to prevent the accessory shaft 32 frombending when exposed to significant loads.

Handpiece 22 has a sleeve-like outer shell 42 in which the motor 24 andother components of the handpiece are housed. A rear drill housing 44,is fitted over the front end of the shell 42 so as to extend forwardlytherefrom. (Hereinafter "forwardly" shall be understood to be along thevector extending from the base end 25 to the head end 27 of thehandpiece 22.) Rear drill housing 44 has a diameter less than that ofthe shell 42 so as to facilitate the seating of the attachment 34 overthe rear drill housing 44. A leaf spring assembly 46 seated in the reardrill housing 44 releasably secures the attachment housing 36 to thehandpiece 22. The shaft 32 of the cutting accessory 26 with which thehandpiece 22 is used is provided with a reduced diameter locking section48 adjacent the butt end thereof. As will be described hereinafter,locking section 48 facilitates the securement of the cutting accessoryto the handpiece motor 24 by a collet 50 (FIG. 4). An actuating collar52 fitted over the rear drill housing 44 controls both the loading andunloading of the cutting accessory 26 to and from the handpiece 22 andthe securing and release of the attachment 34 to and from the handpiece.

The system motor 24, now described by reference to FIGS. 3 and 4,includes a sleeve-like set of windings 54 mounted inside the handpieceshell 42 so as to be disposed against the inside wall of the shell.Motor 24 also includes a rotor shaft 60, illustrated by FIGS. 6A and 6B,that extends outwardly from the center of the windings 54. The shaft 60,includes an elongated stem 62 seated in the base of the outer shell 42.A set of magnets 53 are attached to the shaft stem 62 to provide therequisite magnetization needed to cause the rotor shaft 60 to turn. Anopen ended sleeve 59 is fitted around the magnets 53. In preferredversions of the invention, motor 24 is a brushless, Hallless DC motorwith three distinct windings which are selectively energized in order tocause the rotation of the magnets 53 and rotor shaft 60.

Integral with the shaft stem 62 is a shaft head 66 that has a diameterlarger than that of the stem. The shaft head 66 is formed to define amulti-section bore having an outer bore 68 with a large diameter and aninner bore 70 with a smaller diameter. Threading, (not illustrated) isprovided around the outside of inner diameter bore 70 for a purposedescribed hereinafter. A first, inwardly tapered counter bore 71 islocated between the end of the shaft and large diameter bore section 68.A second inwardly tapered counter bore 72 is located between boresections 68 and 70.

The shaft head 66 is furthered formed so that the forward end thereofhas a inwardly stepped surface 73 that has a diameter less than that ofthe rest of the head. As can best be seen by reference to FIG. 3, thefront end of rotor shaft 60 is rotatably coupled to the housing shell 42by a bearing assembly 76 that is fitted over stepped surface 73. Theouter race of the bearing assembly 76 is loosely fitted around theinside wall of a portion of the housing shell that defines a neck bore78. The rear end of the rotor shaft is coupled to the housing shell 42by a second bearing assembly 77. Bearing assembly 77 is seated in a rearbearing housing 79 that is fitted in the rear end 25 of the outer shell.

A collet housing 80 is coupled to the rotor shaft 60 so as to turn inunison with the shaft, as is depicted by FIGS. 4 and 7. The collethousing 80, is formed out of a single piece of metal and is shaped toform an elongated, cylindrical stem 82. Collet housing stem 82 islocated partially in and extends partially out of rotor shaft head outerbore 68. A threaded mounting stud 84 extends axially rearwardly from theend of the collet housing stem 82. Mounting stud 84 is threadedlycoupled into rotor shaft head inner bore 70 so as to secure collethousing 80 to rotor shaft 60. In still other versions of the invention,mounting stud 84 may be press fitted into a bore of the rotor shaft 60.

Collet housing 80 further includes a solid, main body 88 formedintegrally with the forward end of stem 82 that extends away from rotorshaft 60. The main body 88 has a diameter greater than that of stem 82.Three spaced-apart arms 90 extend outwardly from the outer perimeter ofthe collet housing main body section along axes that are parallel to thecenter axis of the collet housing 80. Each arm 90 includes a basesection 92 with an outer diameter equal to that of the adjacent mainbody 88. Extending from the base section 92 each arm 90 has a first,second and third segments 94, 96, and 98, respectively. The arm firstsegments 94 collectively inscribe a diameter greater than that of themain body 88. The arm second segments 96 collectively inscribe adiameter greater than that inscribed by the first segments 94. The armthird segments 98 collectively inscribe a diameter between thatinscribed by the first segments 94 and the second segments 96. A headring 102 is integrally formed with the arms 90 around the outer ends ofthe arm third segments 98. The head ring 102 is shaped to have an outerdiameter greater than that of the adjacent arm third segments 98. Asmall pilot ring 104 having a diameter less than that of the head ring102 is located over the end of the head ring. Collectively, the insidesurfaces of the arms 90 define a stem receiving space 106 in which theend of the shaft 32 associated with the cutting accessory 26 is seated.The interstitial separations between the housing arms 90 around theoutside of the housing 80 form collet slots 108.

A balancing sleeve 110 is fitted over the portion of the collet housingstem 82 located between the rotor shaft 60 and the collet housing mainsection 88. When the handpiece 22 is in the final stages of assembly,the motor 24 is tested to ensure that the rotor shaft 60 and thecomponents attached to it are properly balanced. If balancing of therotor shaft 60 is required, outer layers of the balancing sleeve 110 canbe selectively removed. Sleeve 110 is further formed to have arelatively thin walled tubular extension 111 that extends forward fromthe outer perimeter of the sleeve.

A cap 112 is fitted over the exposed portion of the collet housing stem82, best seen in FIG. 15A. Cap 112 has a sleeve-shaped body 114 that isloosely fitted into a head bore 116 at the forward end of the handpieceshell 42. Head bore 116 has a diameter greater than that of theadjoining neck bore 78. The end of cap 112 fitted into head bore 116 hasan inwardly directed annular lip 118 that abuts the adjacent bearingassembly 76. The outer end of cap 112 has an outwardly directed annularlip 120.

The collet 50 is now described with reference to FIGS. 4, 8A and 8B. Thecollet 50 is formed out a single piece of flexible metal such asstainless steel. The collet 50 is shaped to have a sleeve like main body124 that is fitted over the collet housing main section 88. An outwardlyextend annular lip 125 extends around the end of the collet main body.The rear portion of the collet main body 124 is seated inside thetubular extension 111 of sleeve 110. A thrust washer 127 is positionedinside tubular extension 110 so as to be located between the inwardlystepped surface of the sleeve 110 and the rearwardly facing surface ofthe lip 125 of the collet 50.

Three equidistantly spaced legs 126 extend forward of the collet mainbody 124. Each leg 126 is seated in a separate one of the collet slots108 so as to be located around the outside of the stem receiving space106 defined within the collet housing 80. A foot 128 is attached to theend of the each collet leg 126. Each foot 128 has a heal 130 thatextends outwardly from the adjoining collet leg 126. More specifically,each heal is formed with a fist outwardly tapered surface 133 adjacentthe surface of the collet leg from which the heal extends. Each healfurther has a second tapered surface 135, with a outwardly directedtaper that is less than that of the first tapered surface, that extendsfrom the end of the first tapered surface to the end of the collet 50.Each collet foot 128 further includes a clamping toe 132 opposite theheal that is positioned to extend inwardly of the associated leg 126 andinto the adjacent stem receiving space 106.

The collet feet 128 are latched in the stem receiving space 106 by acollet ring 136, seen in FIGS. 4 and 9, that is fitted over the upperend of the collet 50. Collet ring 136 has a first, ring shaped lower web138 which is located around the collet legs 126 immediately above thecollet main body 124. Three legs 140 extend forward of the lower web 138and are positioned to extend over the collet legs 126. Each collethousing leg 140 has an outwardly extending foot 142. Each collet housingfoot 142 has an inside surface 144 that extends outwardly relative tothe center of the collet ring 136. The inner surface 144 of a collectfoot and the adjacent inner surface of the associated leg define an edge145. These edge surfaces 145 are positioned to abut the adjacent secondedge surfaces 135 of the collet feet 128. A ring shaped upper web 146extend over the ends of the collet housing feet 142. Upper web 146 isshaped to have an inner surface that fits concentrically around housinghead ring 102.

Collet ring 136 is normally urged upwardly by a spring 150 fitted aroundthe collet main body 124. A rear end of spring 150 bears against colletlip 125. This end of the spring is fitted in the tubular extension 111of bearing sleeve 110. When rotor 60 is actuated, spring 150 engages ina like rotation. Since the rear end of spring 150 is disposed withinsleeve 111, outward vibration of the spring is blocked by the sleeve.The opposed end of the spring 150 bears against the base surface of thecollet ring lower web 138. Since the end of the spring 150 that bearsagainst collet lip 125 is held in position, the opposed end of thespring urges the collet ring 136 upwardly. Thus, the collet ring 136 isnormally positioned so that the ring edges 145 bear against the colletfeet surfaces 135 so as to lock the feet 128 into the collet housingstem receiving space 106. The forward movement on the collet ring 136 isstopped by the action of the top surface of the lower web 138 bearingagainst the annular stepped surface located between the collet housingarms first and second sections 94 and 96, respectively.

A collet actuator 154 selectively displaces the position of the colletring 136 along the length of the collet housing 80 so as to release theclamping force established by the collet 50. The collet actuator 154,now described in detail by reference to FIGS. 4 and 5, includes arelatively large diameter ring shaped base 156 that is disposed aboutspring 150. The outer surface of the collet actuator base 156 is formedto define two, diametrically opposed seating spaces 158. Spaces 158 areeach shaped to have a conical profile to facilitate the partialplacement of separate ball bearings 160 therein. In the depicted versionof the invention, bores 162 are shown at the base of each space 158.Bores 162 are pilot holes that facilitate the machining of the seatingspaces 158 in the collet actuator 154. The inner wall of the colletactuator base 156 is formed with an inwardly oriented flange 157adjacent to the forward end of the actuator 156.

An intermediate ring 159 extends upwardly from the inner perimeter offlange 157. Two diametrically opposed legs 161 extend upwardly from theintermediate ring 159. Legs 161 extend along the outside of the colletring 136. A ring-shaped end web 165 is attached to the end of the colletactuator legs 161. The legs 161 are dimensioned so that collet actuatorweb 165 is located above the collet ring upper web 146. The colletactuator web 165 is dimensioned so that the web 165 can be pressedagainst the collet ring upper web 146.

A spring 167, best seen in FIG. 15A, extends between the body 114 of cap112 and the undersurface of the base 156 of the collet actuator 154.Spring 167 biases the collet actuator 154 forwardly so as to prevent theactuator for inadvertently releasing the locking force the collet 50imposes of the shaft 32 of the cutting accessory 26.

Collet actuator 154 is slidably fitted inside the rear drill housing 44now described with reference to FIGS. 5, 10A and 10B. Rear drill housing44 includes a base section 168 that has an outer diameter equal to theouter diameter of the adjacent handpiece shell 42. The rear drillhousing base section 168 is securely fitted to the outer shell 42 of thehandpiece 22 by an adapter ring 163 best seen by reference to FIG. 15A.Adapter ring 163 has a generally sleeve-like shape. Adapter ring iscompression secured around the reduced diameter front end of the outershell 42. The inner wall of the base section 168 of the rear drillhousing 44 and the outside of the adapter ring 163 are provided withthreading to facilitate the coupling of the handpiece to the adapterring.

Immediately above rear drill housing base section 168 is a intermediatesection 169 that has diameter less than that of the base section. Reardrill housing intermediate section 169 is formed to define twodiametrically opposed slots 170 that extend through rear drill housing44. Each ball bearing 160 travels in one of the slots to cause thedisplacement of the collet actuator 154 and the unlocking of the collet50. Each slot 170 is formed with a first, main section 172 that extendshelical downwardly from a point below the top of the housingintermediate section 169. Contiguous with each slot main section 172 isa detent 174. Relative to the adjoining main sections 172, the detents174 extend upwardly a small distance upwardly so as to function as aball stop space in which the ball bearing 160 can be seated. Each slot170 is further formed with an release section 178 that extends helicaldownwardly a small distance from the detent 174.

Contiguous with the top of the rear drill housing intermediate section169 is a inwardly tapered transition ring 180. The transition ring 180and adjacent portion of the rear drill housing intermediate section 169are shaped to define a set of slots 182 that are distributed around theouter circumference of the rear drill housing 44. As will be discussedhereinafter, slots 182 are dimensioned to receive inwardly directedteeth integral with the attachment housing 36. An annular groove 184 isformed in the rear drill housing intermediate section 168 to facilitatethe attachment of a retaining ring 185 (FIG. 15B) the purpose of whichwill be described hereinafter.

A constant diameter stem section 188 extends upwardly from the end ofrear drill housing tapered transition ring 180. The open end of the reardrill housing stem section 188 is formed to have an annular, inwardlystepped surface 190. Rear drill housing 44 is formed with twodiametrically opposed, elongated leaf spring slots 192. Each leaf springslot 192 extends from the base of the stem section stepped surface 190,through the stem section 188 and through the transition ring 180. Eachleaf spring slot 192 then terminates in the intermediate section 169immediately below the level at which the adjacent rear drill housingslots 182 terminate. Leaf spring slots 192 are shaped so as to have arelatively shallow depth adjacent the top of the drill housing stemsection 188. In this section of the rear drill housing 44 there is ahead 194 within the forward end of stem 188. Rearward from head 194,each leaf spring slot 192 extends through the rear drill housing 44directly into the void space within the center of the stem 188.

The leaf spring assembly 46 is fitted over rear drill housing 44 so asto be substantially flush with the outer surface of the rear drillhousing. The leaf spring assembly 46, now described with reference toFIGS. 5 and 11, includes a head 198 that is generally cylindricallyshaped. The head 198 of the leaf spring is seated around the top of thedrill housing stem section 188 in the space defined by the inwardlystepped surface 190. Extending downwardly from the head 198 and seatedin the lead spring slots 192 are two leaf spring legs 202. Each leafspring leg 202 is formed with an outwardly extending locking tab 204located adjacent the drill housing transition ring 180. The tabs 204 areformed with top surfaces 206 that are dimensioned to be flush with theouter surfaces of the adjacent transition ring 180. Each locking tab 204is further formed with a bottom surface 207 that extends perpendicularlyoutward from the leaf spring leg 202. The locking tab bottom surfaces207 are the surfaces of the leaf spring 46 against which the attachmenthousing 36 actually abuts.

An outwardly extending foot 208 is integrally attached at the bottom ofeach leaf spring leg 202 so as to be spaced below the associated locktab 204. Each foot 208 is formed with an outer surface 210 that extendsdiagonally outwardly away from the associated leg 202. The leaf springlegs are further formed to have heals 212 that extend from immediatelybelow the locking tab 204 to immediately above the base of theassociated foot 208. Heals 212 provide structural rigidity to the lowerportion of each leaf spring leg 202. Also, as discussed hereinafter,heals 212 cooperate with collet actuator 154 to prevent unintentionalinward movement of the legs 202 of the leaf spring 46.

The cylindrical actuating collar 52, now described with reference toFIGS. 5 and 11, both controls the loading of the cutting accessory 26and the release of the attachment 34. The actuating collar 52 isgenerally sleeve-like in shape and is rotatably fitted around the drillhousing intermediate section 169. Retaining ring 185 (FIG. 15B) which issnap fitted in groove 184 formed in the rear drill housing 44, holds theactuating collar 52 in position. In the depicted version of theinvention, retaining ring 185 is backed up by a washer 187.

The actuating collar 52 has an outer surface 218 formed with raisedbumps to facilitate manual rotation of the collar. Actuating collar 52is further shaped to have a generally cylindrical, constant diameterinner wall 220 that extends substantially the entire length of thecollar. Inner wall 220 is formed to define two diametrically opposedball grooves 222 each of which extend the along the length of the innerwall. The ball grooves 222 are dimensioned to each receive one of theball bearings 160.

The interior of actuating collar 52 is further shaped to have anannular, outwardly stepped surface 224 that is located around the top ofthe collar adjacent the inner wall 220. Stepped surface 224 isdimensioned to have a diameter greater than that of the adjacent innerwall 220. The leaf spring feet 208 are seated in the space in theactuating collar 52 defined by the top of the inner wall 220 and theadjacent stepped surface 224. A pair of diametrically opposed tabs 226,integrally formed with actuating collar 52 extend inwardly from collarstepped surface 224 towards the center axis of the collar 52. Each tab226 is formed with a surface 228 that extends diagonally away from theadjacent stepped surface 224. As will be discussed hereinafter, whenactuating collar 52 is rotated, each tab surface 228 is forced againstone of the outer surfaces 210 integral with the leaf spring feet 208.

Referring to FIG. 15A, it can be seen that a nut-like front drillhousing 230 is secured to the open top end of the stem section 188 ofthe rear drill housing 44. Front drill housing 230 has a outwardlydirected circumferential flange 231. A spacer ring 232 and drag ring 233are fitted around the outside of the front drill housing so as to belocated between the top of the head 198 of the leaf spring assembly 46and the rear surface of front drill housing flange 231. Spacer ring 232is pressed against the head 198 of the leaf spring assembly 46. Thespacer ring 232 has a generally T-shaped cross section profile so as todefine a seating surface against which the body of the front drillhousing 230 abuts. Drag ring 233 is located between spacer ring 232 andthe flange 231 of front drill housing 230. While not illustrated, dragring 233 is formed as a split ring.

A preload plunger 234 is slidably fitted in a bore 235 formed in thefront drill housing 230. Preload plunger 234 is shaped so that the rearend thereof has an outwardly directed lip 236. The lip 236 of thepreload plunger 234 is dimensioned to abut against a complementary step237 formed in the bore of the front drill housing 230 that limits theforward movement of the preload plunger. Preload plunger 234 has anaxially extending bore 238 designed to accommodate the shaft 32 of thecutting attachment 26. The exposed tip of the preload plunger is formedwith an inwardly beveled surface 239 around bore 238.

A bearing assembly 240 is seated in a stepped space 241 (FIG. 10B)formed in head 194 of drill housing 44. Bearing assembly 240 provides alow friction interface between the shaft 32 of the cutting attachment 26and the rear drill housing 44. A washer 243 rests on the top surface ofbearing assembly 240. A spring 242 extends between washer 243 and astepped surface inside the preload plunger 234 disposed around bore 238.Spring 242 urges preload plunger 234 in the forward direction.

The attachment 34 in which a substantial length of the cutting accessorystem 32 is housed, is now described by reference to FIGS. 12 and 16. Theattachment housing 36 is fitted over both drill housings 44 and 230. Aretainer 248 is fitted over the rear circumferential surface of theattachment housing 36. Retainer 248 has an inwardly directed lip 249that is spaced rearwardly away from the end of the attachment housing36. Lip 249 is shaped to define the teeth 250 that fit into thecomplementary slots 182 formed in the rear drill housing 44.

Attachment housing 36 is formed to have a generally constant diameterbase section 252. There is an inwardly tapered section 254 contiguouswith the base section 252. The attachment housing 36 is further formedso as to have a constant diameter main space 262. The stem section 188of the rear drill housing 44 is seated in space 262. Attachment housing36 is further formed to have a reduced diameter space 263 inside taperedsection 254. A bore 264 extends forward from space 263. Space 262, space263 and bore 264 are coaxial with each other and extend through theattachment housing 36.

Sleeve 38 extends through bore 264. The sleeve 38 is formed with anoutwardly extending lip 265 that abuts the surface of the attachmenthousing 36 that defines space 263. A bearing retainer ring 266 seated inspace 263 holds sleeve 38 in position. A first bearing assembly 267 isfitted in the rear end of the sleeve 38 so as to abut bearing retainerring 266. A tube-like bearing sleeve 268 is fitted within attachmentsleeve 38 so as to abut bearing assembly 267. A bearing preload ring 269is located above bearing sleeve 268. A second bearing assembly 267 islocated adjacent preload ring 269. A preload sleeve 270 is locatedadjacent the second bearing assembly 267. Third and fourth bearingassemblies 267 are located in tandem adjacent preload sleeve 270. A nosecap 271 is fitted over the open end of sleeve 38 so as to abut theforwardmost, fourth bearing assembly 267. A spring 273 fitted in bearingsleeve 268 abuts the adjacent preload ring 269. Spring 273 imposes anaxial force across the races of the forward bearing assembly 267 so asto reduce bearing chatter.

The shaft 32 of the cutting accessory 26, as seen now by FIGS. 13A and13B, has a butt end 284 which is seated in the shaft receiving space 106of collet housing 80. Between the shaft butt end 284 and the rest of theshaft 32 is the shaft locking section 48 formed as a solid sectionintegral with the rest of the shaft 32. Shaft lock ring 48 is shaped tohave a number of flat faces 290 which are all recessed relative to theadjacent outer surfaces of the adjacent butt end 284 and the rest of theshaft 32. In the depicted version of the invention, shaft lockingsection 48 has six faces 290. Shaft lock ring 48 is further formed so asto have four rounded corners 292 between four pairs of adjacent faces290. There are also two, diametrically opposed corners 294 with sharp,straight edges located between the remaining two pairs of abutting faces290. The corners 294 with the straight edges are located further fromthe center axis of the shaft 32 than the corners 292 with the roundededges.

When the surgical tool system 20 of this invention is assembled for use,attachment 34 is seated over drill housings 44 and 230 and the cuttingaccessory shaft 32 is positioned so as to extend through the attachmentand into the drill housings. As seen in FIG. 15A, the attachment 32 ispositioned over the rear drill housing 44 so that the lock ring teeth250 associated with the attachment housing 34 are fitted into the drillhousing slots 182. When the attachment housing 34 is so positioned, theleaf spring locking tabs 204 are seated over two of the opposed lockring teeth 250 so as to hold the attachment housing 34 in position.Moreover, when the attachment housing 34 is so positioned, the heels 212of the leaf spring feet 208 are in close proximity to the adjacent outersurface of the intermediate section 159 of the collet actuator 154 asseen in FIG. 14A. The relative position of collet actuator 154 to feet208 of the leaf spring assembly 46 prevents motor or cutting inducedvibration of handpiece 22 from causing the feet to move inwardly andpotentially release their hold on attachment 34.

The butt end 284 of the shaft 32 of the cutting accessory 26 is seatedin the shaft receiving space 106 formed in the collet housing 80. Shaft32 is locked in the housing by the action of the collet feet 128 bearingagainst three of the faces 290 formed in the shaft locking section 48.The collet ring 136 is latched in position against the collet legs 126by the biasing force imposed by the spring 150. Consequently, the forceof the edge surfaces 145 of the collet ring moving against the surfaces135 of the collet feet produces the griping action of the collet feet128. When the surgical tool system 20 is in the run state, ball bearings160 are in their highest position along the actuating collar ballgrooves 222. When ball bearings 160 are in this position, the ballbearings hold the collet actuator 154 in its most distal positionrelative to the rear drill housing 44. When the collet actuator 154 isin this position, the actuator web 165 is spaced above the adjacentcollet ring upper web 146.

When the surgical tool system 20 is so assembled, the tool can be usedin a conventional manner. Since the collet actuator web 165 is spacedfrom the adjacent collet ring upper web 146, the collet ring 136 as wellas the associated elements attached thereto, the collet 50, collethousing 80, rotor shaft 60 and rotor 56 can then freely turn whenenergization voltages are applied to the windings 54 of the motor 24.Since the collet 50 firmly holds the shaft 32 in the collet housing 80,the motor-induced rotation of the collet housing 80 is thus transferredto the shaft. In this manner, the motive force generated by the motor 24is thus transferred to the cutting accessory 26.

When the physician using the tool system 20 of this invention wishes touse it with a different cutting accessory 26, all that is necessary todo is to rotate the actuating collar 52. The actuating collar 52 causesthe ball bearings 160 to move helical downwardly through the mainsections 172 of the slots 170 formed in the rear drill housing 44. Asrepresented by FIG. 15B, the downward movement of the ball bearings 160forces the collet actuator 154 to undergo a similar rotating movementdownward along the axis of the handpiece 22. As the ball bearings 160are displaced through the slots 170, they will seat in the detents 174.The seating of ball bearings 160 in the detents 174 serves to lock theactuating collar 52 in place, in an accessory load state.

As the collet actuator 154 moves downwards, the actuator web 165 abutsagainst the collet ring upper web 146, best seen by reference to FIG.15B. The continued movement of the collet actuator 154 forces the colletring 136 downwardly so as to result in the compression of the spring 150that abuts the ring 136. As the collet ring 136 moves downwards, awayfrom the heels 130 of the collet feet 128, the collet legs 126 open upso that the collet feet move out of the shaft receiving space 106. Themovement of the collet feet 128 out of the shaft receiving space 106 andaway from the shaft butt end 284 frees the shaft 32 so that the cuttingaccessory 26 can be removed from handpiece 42.

Once the first cutting accessory 26 is removed from the handpiece 22, asecond accessory can be loaded in place. Once the shaft 32 of the newaccessory 26 is fitted in the handpiece 22, actuating collar 52 ismanually rotated back to its initial, run, position. This movementcauses the collet actuator 154 to be displaced upwardly so as to allowthe collect ring 136 to return to its initial position. As the colletring 136 returns to its normal position, the edges surfaces 145 of thelegs 140 of the collet ring 136 force the feet 128 of the collet 50inward towards the center of the shaft receiving space 106. The inwardmovement of the collet feet 128 forces them against the faces 290 of theshaft locking section 48 so as to lock the replacement cutting accessory26 in position.

If the physician desires to replace the attachment 34 of the surgicaltool system 20, actuating collar 52 is initially rotated in the mannerrequired in order to unload the cutting accessory 26. The physician thencontinues to rotate actuating collar 52 so that the ball bearings 160are displaced beyond the detents 174 and into the release sections 178of slots 170. As a result of this further rotation of actuating collar52, the tabs 226 associated with the collar stepped surface 224 areforced against the adjacent leaf spring feet 208 (FIG. 14B). Also, owingto the vertical displacement of the collet actuator 154, the actuator154 is now spaced so that the leaf spring legs and feet 202 and 208,respectively are aligned with the interstitial spaces between the legs161 of the actuator 154. Thus, the action of the tabs 226 moving againstthe leaf spring feet 208 forces the leaf spring legs 202 inwardlyrelative to the adjacent outer surface of the rear drill housing 4 asrepresented by FIG. 15C. The handpiece 22 is, at this time in theattachment release state. Once leaf spring legs 202 are disposed intothe associated slots 192 formed in the rear drill housing 44, theattachment 34 is forced upwards a short distance by the action of thepreload plunger 234 bearing against bearing retainer ring 266. Theforward movement of the attachment housing 34 is, however, damped by thefrictional contact imposed by the drag ring 233 against the adjacentsurface of the attachment 34.

When the actuating collar 52 is in the attachment release state, theball bearings 160 are in the base of the release sections 178 of slots170. The release of the manual force on the actuating collar 52 allowsthe force imposed by springs 150 and 167 through the collet actuator 154causes the actuating collar 52 to rotate backwards so as to take theleaf spring assembly 46 out of the attachment release state. Morespecifically, the actuating collar 52 will continue to rotate until theball bearings 160 are seated in detents 174 so that the collet 50remains in the accessory load state until otherwise actuated.

After the first attachment 34 is removed from the handpiece 22, theactuating collar 52 is returned to its original position. Thereplacement attachment 34 is then secured into position by simply snaplocking it in place over the rear drill housing 44. A new cuttingaccessory 26 is then coupled into the handpiece 22. Once the new cuttingaccessory 26 is in place, the actuating collar 52 is manually actuatedto return the handpiece from the accessory load state back to the toolrun state.

The surgical tool system 20 of this invention thus provides a convenientsystem for using different cutting accessories 26 and differentattachments 34 with a single handpiece 22. The cutting accessory 26 iscoupled to the handpiece 22 for rotation with the rotor shaft 60 bycollet 50. The attachment 34 is statically secured to the handpiece 22by leaf spring 46. In the event there is a need to change the cuttingaccessory 26 or the attachment 34, all the surgical personnel have to dois rotate the actuating collar 56. No additional tools are required tochange either the accessory or the attachment.

Furthermore, the handpiece 22 of this invention only has a singlecomponent, the actuating collar 52, that needs to be manipulated inorder to change the cutting accessory 26 or the attachment 34. Sincethere is only one actuatable element attached to the handpiece 22,surgical personnel do not have to spend any time remembering whichbutton or collar needs to be manipulated in order to switch thecomponents used with the handpiece 22.

Moreover, still another feature of this invention is that once theactuating collar 52 is rotated into the accessory load state, the ballbearings 160 seat in the complementary detents 174 and are in held inthis position by the force that springs 150 and 167 indirectly impose oncollet actuator 154. Consequently, surgical personnel handling thehandpiece 22 do not have to continue to hold the actuating collar 52 toensure that the collet feet 128 remain in the unloaded state. Byeliminating the need to have to hold the actuating collar 52 in theaccessory load state, the surgical personnel can more closely focus onrapidly replacing the surgical cutting accessory 26. In a similar vein,all that is necessary to do fit a replacement attachment 34 to thehandpiece is to snap fit the attachment in place.

Collectively, the elimination of multiple release actions, any need tohold the collet in the accessory loaded state or the leaf springassembly 46 in the attachment release state serve to minimize the amountof time and effort surgical personnel need to take in order to changethe tools and attachments with which this handpiece is used.

Still another feature of the system 20 of this invention is that whenthe actuating collar 52 is in any other position more than a few degreesoff from the drill run state, the movement of the collar 52 forces thecollet actuator 154 to abut against the collet ring 136. When thehandpiece 22 is in this state, the force of the collet actuator 154abutting the collet ring 136 prevents rotation of the collet ring andthe components attached thereto. As a result of this breaking action, ifthe motor 24 is inadvertently actuated when the handpiece 22 is in thisstate, the collet rotor and all the elements attached thereto includingthe motor rotor 60 are prevented from moving. This serves as a fail safeto prevent the motor from inadvertently being used to supply rotationalforce to the accessory shaft when the accessory shaft is not properlylocked in position.

The shape of the locking section 48 of the shaft 32 of the cuttingaccessory 26 also facilitates the rapid changing of the accessories. Thereduced diameter rounded corners 292 of the lock ring 48 ensure that ifthe shaft 32 is not properly seated in the collet housing 80, the feet128 of the collet 50 will upon closing, first strike the corners 294with sharp edges. This will cause the shaft to rotate until each foot isin contact with a flat surface 290. Thus, this feature of the inventionsubstantially reduces the possibility that the each of the collet feet128 will not press against a complementary flat surface 290.

FIG. 17 depicts an angled attachment 300 that can be used with thesurgical tool system 20 of this invention. Attachment 300 has a base 302with a retainer (not illustrated) designed to perform the function ofpreviously described retainer 248. A drive shaft 304 is rotatably fittedto the base 302 and extends rearwardly therefrom. Drive shaft 304 isprovided with a locking section 306 with surfaces similar to thesurfaces similar to locking section 48 (FIG. 13B). In the illustratedversion of the invention the flat faces that form locking section 306extend to the butt end of shaft drive shaft 304. The drive shaft 304 iscoupled into the collet housing 80 in a manner identical to that bywhich the shaft of a surgical tool is so secured.

A top section 307 integral with and angled from the base 302 extendsforward the base. A coupling assembly similar to the described collet50, collet housing 80, collet ring 136 and collet actuator 154 aredisposed inside the top section 307 of the angled attachment 300 tofacilitate the rotatable coupling of the stem 32 of a cutting accessory26 thereto. An actuating collar 308 located around the outside of thetop section is employed to move the coupling assembly between the loadedand unloaded states.

Also disposed within attachment 300 is a gear assembly for transferringthe rotational moment of drive shaft 304 to the coupling assembly. Thus,the drive shaft 304, the gear assembly and the coupling assemblycollectively transfer the rotational moment of the motor 24 of thehandpiece 22 to the cutting accessory 26 attached to the angledattachment 300.

The foregoing description has been limited to a specific embodiment ofthis invention. It will be apparent, however, from the description ofthe invention that it can be practiced using components different fromwhat has been described. For example, while in the described version ofthe invention, the motor 24 is an electrically actuated motor, in otherversions of the invention the rotor shaft may either be drivenpneumatically, hydraulically or mechanically. Furthermore, while in thedescribed version of the invention a collet 50 with resilient feet 128is employed to lock the shaft 32 of the cutting accessory 26 in place,in other versions of the invention, other locking members may beemployed. For example, it may be possible to replace the collet withball bearing or a set of spring loaded locking pins.

Also, the disclosed arrangement of the components of the componentsshould likewise be recognized as exemplary. In some versions of theinvention it may be possible, for example, to position the colletactuator so that it moves forward so as to cause the collet ring orsimilar component in a forward direction away from the collet 50.

Also, while only two attachments 34 and 300 for use as part of thesurgical tool system 20 have been shown, others may, of course, beprovided. For example, it may be desirable to provide an elongatedattachment with a single axis centered on the axis of the handpiece 22.This would allow the cutting attachment to be positioned a relativelylong distance away from the end of the handpiece 22. This attachmentwould have a drive shaft and a coupling assembly similar to thepreviously described angled attachment 300. Still other attachmentscould be provided with internal gear assemblies to convert the circularmotion of the rotor shaft 60 into oscillating motion that wouldfacilitate the use of handpiece with surgical cutting blades designed tomove in sagittal pattern (in a plane parallel with the axis of thehandpiece) or in an oscillatory motion (accessory movement in a planeangled from the axis of the handpiece). These attachments could then beused to attach saw blades to the handpiece 22 so that the saw bladescould function as the cutting accessories 26. It should, of course,different angled attachments other than attachment 300 may be provided.For example, it may be possible to provide an angled attachment thatfacilitates the coupling of a cutting accessory to the handpiece at aright angle relative to the center axis of the handpiece 22.

Moreover, the locking section 48 of the shaft 32 of the cuttingaccessory 26 can have other shapes than what has been described. Forexample, it may be desirable to simply provide additional, relativelysmall facets instead of the described rounded corners. Also, it may bepossible to shape the locking section so that four of the corners arespaced further from the center axis of the shaft than the other twocorners. Moreover, while in the described version of the invention thelocking section has six flat faces 290, other versions of the inventionmay have more or less faces and even an odd number of faces.

Therefore, it is the object of the appended claims to cover all suchmodifications and variations as come within the true spirit and scope ofthe invention.

What is claimed is:
 1. A surgical handpiece adapted for use with areplaceable cutting accessory, the cutting accessory having a shaft,said handpiece comprising:an outer shell; a motor disposed in said outershell, said motor having a rotating shaft; a coupling assembly attachedto said outer shell and fitted to said motor, said coupling assemblyincluding:a housing coupled to said rotating shaft of said motor torotate with said shaft, said housing having an axially extending shaftbore for receiving the shaft of the cutting accessory, and said housingshaped to form at least one opening that extends into said shaft bore; alocking member positioned adjacent each said opening in said housing forselective positioning in said shaft bore of said housing so that whensaid locking member is positioned in said shaft bore of said housing,said locking member holds the shaft of the cutting accessory forrotation with said shaft of said motor and when said locking member isspaced from said shaft bore, the shaft of the cutting accessory isremovable from said shaft bore of said housing; a lock ring disposedaround said housing and displaceable along said housing from a firstposition wherein said lock ring abuts said locking member so as to latchsaid locking member into said shaft bore of said housing and a secondposition wherein said lock ring is spaced from said locking member; abiasing member that normally urges said lock ring into said lock ringfirst position; a lock ring actuator disposed around said lock ring forselectively abutting said lock ring to move said lock ring from saidlock ring first position to said lock ring second position; and adisplaceable actuating member that is fitted over said outer shell andcoupled to said lock ring actuator, said actuating member being movablebetween a run position and an accessory load position, wherein when saidactuating member is moved from said run position to said accessory loadposition, said actuating member causes said lock ring actuator to abutsaid lock ring so as to cause said lock ring to move to said lock ringsecond position and said actuating member remains in said accessory loadposition until displaced from said accessory load position.
 2. Thesurgical handpiece of claim 1, wherein said actuating member of saidcoupling assembly is a collar fitted around said outer shell so as torotate around said outer shell.
 3. The surgical handpiece of claim 2,further including a coupling member extending between said collar andsaid lock ring actuator for converting rotary motion of said collar intoaxial motion that displaces said lock ring actuator and wherein saidcoupling member extends through a slot formed in said outer shell, saidslot being formed with a detent in which said coupling member seats whensaid collar is moved to said accessory load position.
 4. The surgicalhandpiece of claim 3, wherein said coupling member is a ball bearing. 5.The surgical handpiece of claim 1, wherein:said locking member of saidcoupling assembly comprises a collet that is fitted around said housingof said coupling assembly, said collet being shaped to have at least twospring biased legs, each said leg of said collet being positioned to fitin a separate opening formed in said housing of said coupling assemblyand having a foot that is positioned to be urged into said shaft boreformed in said housing, said feet of said collet being configured tosecure the shaft of the cutting accessory into said shaft bore of saidhousing; said lock ring of said coupling assembly is a slidable ringthat is fitted over said legs of said collet to selectively lock saidfeet of said collet into said shaft bore formed in said housing of saidcoupling assembly; and said actuating member is axially slidable oversaid lock ring so as to selectively move said lock ring from said firstposition of said lock ring to said second position of said lock ring. 6.The surgical handpiece of claim 5, wherein said actuating member of saidcoupling assembly is a collar fitted around said outer shell so as torotate around said outer shell.
 7. The surgical handpiece of claim 1,wherein said coupling assembly further includes:an end cap attached to afront end of said outer shell for receiving the shaft of the surgicaltool and a replaceable attachment unit; an attachment locking assemblysecured to said end cap and extending outwardly therefrom for securingthe attachment unit to said handpiece, said attachment locking assemblyhaving a locked state in which said attachment locking assembly holdsthe attachment unit to said handpiece and a release state in which saidattachment locking assembly allows the attachment unit to be removedfrom said handpiece; and wherein said actuating member of said couplingassembly is connected to said attachment locking assembly forcontrolling the locked/release state of said attachment lockingassembly.
 8. The surgical handpiece of claim 7, wherein when saidactuating member of said coupling assembly is in said run position, saidattachment locking assembly is in said locked state and is furtherconfigured so as to cause said attachment locking assembly to transitionfrom said locked state to said release state only after said actuatingmember is initially moved to said accessory load position.
 9. Thesurgical handpiece of claim 7, wherein:said actuating member of saidcoupling assembly is a collar fitted around said outer shell so as torotate around said outer shell; a coupling member extends between saidcollar and said lock ring actuator for converting the rotary motion ofsaid collar into axial motion that displaces said lock ring actuator,wherein said coupling member extends through a slot formed in said outershell, said slot being formed with a detent in which said couplingmember seats when said collar is moved to said accessory load position;and said collar forming said actuating member is further configured tobe moved from a first, run state position to said accessory loadposition and then to said attachment release position.
 10. The surgicalhandpiece of claim 7, wherein:said locking member of said couplingassembly comprises a collet that is fitted around said housing of saidcoupling assembly, said collet being shaped to have at least two springbiased legs, each said leg of said collet being positioned to fit in aseparate opening formed in said housing of said coupling assembly andhaving a foot that is positioned to be urged into said shaft bore formedin said housing, said feet of said collet being configured to secure theshaft of the surgical tool into said shaft bore; said lock ring of saidcoupling assembly is a slidable ring that is fitted over said legs ofsaid collet to selectively lock said feet of said collet into said shaftbore formed in said housing of said coupling assembly; and saidattachment locking assembly includes a spring member that is normallyoutwardly biased to hold the attachment unit to said handpiece.
 11. Asurgical handpiece adapted to receive a shaft of a cutting accessory andan attachment head, wherein the shaft of the cutting accessory extendsfrom the attachment head, said handpiece comprising:an elongated outershell having an open front end; a motor disposed in said outer shell,said motor having a rotating shaft oriented towards said front end ofsaid outer shell; a drill housing fitted over said open front end ofsaid outer shell, said drill housing having a center opening forreceiving the shaft of the cutting accessory and being dimensioned to befitted into the attachment head; an attachment locking assembly attachedto said drill housing, said attachment locking assembly having at leastone locking foot that extends outwardly from said drill housing, said atleast one locking foot having a first, locking position wherein said atleast one locking foot engages the attachment head so as to secure theattachment head to said drill housing and a second, release positionwherein said locking foot is spaced from said attachment head so as toallow the removal of the attachment head from said drill housing; ashaft coupling assembly disposed in said outer shell and connected tosaid shaft of said motor for securing the cutting accessory shaft to theshaft of said motor for rotation therewith, said shaft coupling assemblyhaving a first, run state wherein the cutting accessory shaft is securedto said shaft of said motor and a second, load state wherein saidcutting accessory shaft can be removed from said shaft couplingassembly; and a single, manually controlled actuating member connectedto said attachment locking assembly and said shaft coupling assembly forcontrolling the states of said attachment locking assembly and of saidshaft coupling assembly, wherein said actuating member is movablebetween a first position in which said at least one locking foot of saidattachment locking assembly is in said locking position and saidcoupling assembly is in said run state, a second position in which saidat least one locking foot of said attachment locking assembly remains insaid locking position while said shaft coupling assembly transitions tosaid load state and a third position wherein said at least one lockingfoot of said attachment locking assembly transitions to said releaseposition.
 12. The surgical handpiece of claim 11, wherein said actuatingmember is a rotating collar.
 13. The surgical handpiece of claim 12,wherein said locking member of said attachment locking assembly is anoutwardly biased spring and said rotating collar is configured to urgesaid locking member inwardly when said rotating collar is displaced intosaid third position of said actuating member.
 14. The surgical handpieceof claim 11, wherein said actuating member is configured to latch intosaid second position when being so displaced from said first position.15. The surgical handpiece of claim 14, wherein said actuating member isfurther configured to automatically return to said second position uponbeing released from force holding said actuating member in said thirdposition.
 16. The surgical handpiece of claim 11, wherein said shaftcoupling assembly includes:a housing coupled to said shaft of said motorto rotate with said shaft, said housing having an axially extendingshaft bore for receiving the shaft of the cutting accessory, and saidhousing is shaped to form at least one opening that extends into saidshaft bore; a locking member positioned adjacent said opening in saidhousing for selective positioning in said shaft bore of said housing sothat when the shaft of the cutting accessory is in said shaft bore, saidlocking member holds the shaft of the cutting accessory for rotationwith said housing and when said locking member is spaced from said shaftbore, the shaft of the cutting accessory is removable from said shaftbore; a lock ring disposed around said housing and displaceable alongsaid housing from a first position wherein said lock ring abuts saidlocking member so as to latch said locking member into said shaft boreof said housing and a second position wherein said lock ring is spacedfrom said locking member; a biasing member that normally urges said lockring into said lock ring first position; and a lock ring actuatordisposed around said lock ring for selectively abutting said lock ringto move said lock ring from said lock ring first position to said lockring second position, wherein said lock ring actuator is connected tosaid actuating member so that when said actuating member is moved fromsaid first position of said actuating member to said second position,said lock ring actuator is displaced against said lock ring.
 17. Thesurgical handpiece of claim 16, wherein said actuating member is arotating collar.
 18. The surgical handpiece of claim 16, wherein saidlock ring actuator is positioned to abut said at least one locking footof said attachment locking assembly when said actuating member is insaid first position so as to prevent said at least one locking foot frombeing displaced from said locking position and said lock ring actuatoris further positioned to move away from said at least one locking footof said attachment locking assembly as said actuating member moves fromsaid second position to said third position so as to allow said at leastone locking foot to move from said locking position to said releaseposition.
 19. The surgical handpiece of claim 16, wherein said biasingmember of said shaft coupling assembly is configured to latch saidactuating member into said second position when said actuating member ismanually displaced from said first position into said second positionand is further configured to automatically return said actuating memberto said second position when manual force holding said actuating memberin said third position is released.
 20. The surgical handpiece of claim19, wherein said locking member of said attachment locking assembly isan outwardly biased spring and said actuating member is configured tourge said locking member inwardly when said actuating member isdisplaced into said third position of said actuating member.
 21. Thesurgical handpiece of claim 20, wherein said actuating member is arotating collar.
 22. A surgical tool system comprising:a cuttingaccessory; an attachment having an attachment housing for releasablyreceiving said cutting accessory; a rotating shaft that extends fromsaid attachment housing, said rotating shaft being coupled to thecutting accessory for transferring rotational power thereto; and ahandpiece to which said attachment and said rotating shaft arereleasably secured, said handpiece including:an outer shell; a motordisposed in said outer shell, said motor having a rotating rotor; ashaft coupling assembly attached said rotor of said motor, said shaftcoupling assembly being configured to releasably secure said rotatingshaft thereto for rotation with said rotor; an attachment lockingassembly secured to said outer shell, said attachment locking assemblybeing configured to hold said attachment locking assembly thereto in astatic position and including a selectively displaceable lock member forengaging said attachment housing so as to hold said attachment to saidattachment to said handpiece; and an actuating collar rotatably securedto said outer shell of handpiece, said attachment collar being connectedto said coupling assembly and said attachment locking assembly wherebywhen said attachment collar is moved from a first position to a secondposition, said attachment collar causes said coupling assembly torelease said rotating shaft and when said attachment collar is movedfrom said second position to a third position, said attachment collarcauses said locking member of said attachment locking assembly todisengage from said attachment housing.
 23. The surgical tool system ofclaim 22, further including a biasing member integral with saidhandpiece for holding said actuating collar in said second position ofsaid actuating collar.
 24. The surgical tool system of claim 23, whereinsaid biasing member of said handpiece is further configured to urge saidactuating member from said third position of said actuating member backto said second position of said actuating collar.
 25. The surgical toolsystem of claim 22, wherein: said rotating shaft is integrally attachedto said cutting accessory and said attachment housing is formed todefine an elongated bore for releasably positioning said rotating shaftthereto.
 26. The surgical tool system of claim 22, wherein said couplingassembly of said handpiece includes a displaceable coupling actuator,said coupling actuator being connected to said actuating collar of saidhandpiece so as to be displaced by rotation of said actuating collar andwherein said coupling actuator is configured to abut a member attachedto said rotor of said motor when said actuating collar is displaced fromsaid first position of said actuating collar so that when said couplingactuator abuts said member attached to said rotor, said couplingactuator prevents said rotor from rotating.